This invention relates to a method and apparatus for the cooling of bulk or draught beverages such as beer, lager, water, soft drinks etc., from a bulk container such as a keg or tank prior to dispensing at a device such as a tap.
With known dispensing systems comprising a closed loop incorporating a cooling unit and at least one dispensing tap (cf U.S. Pat. No. 4,216,879, WO97/28082), into which loop beverage is fed from a bulk container in accordance with dispensing demand, the rate of dispensing is frequently such that the cooling capacity of the cooling unit is exceeded, and the temperature of the then dispensed beverage rises beyond an optimum, target temperature.
An object of the present invention is the provision of an improved method and apparatus for the cooling of bulk or draught beverages to a target dispensing temperature.
According to a first aspect of the present invention, there is provided a method of cooling bulk or draught beverages prior to dispensing comprising:
(i) introducing the beverage from a bulk container into a circulation loop that incorporates a pump, and a cooling unit, and
(ii) returning cooled beverage as a heat exchange medium to a heat exchange unit associated with the container, whereby the residual beverage in the container is itself cooled by the returning cooled beverage.
In this way, after a period of time, both the residual beverage in the container and the beverage and the loop are at the same, or generally the same, temperature.
Thus, with the method in accordance with the invention, the beverage contained in the loop is itself used as the heat exchange medium of the heat exchange unit for cooling the residual beverage within the container. In practice, with say  less than 1-gallon of beverage contained in the loop, the cooling unit, and the heat exchange unit, circulating as a cooling medium, the remaining say 10-gallons in a keg is gradually cooled, e.g. overnight, until an even temperature is attained, when the beverage is ready for dispensing. The temperature of the beverage in the loop, the cooling unit, and the heat exchange unit assists in maintaining the sought lower temperature, as the residual cooled beverage in the keg(s) is effective as a heat sink, being effective on the heat exchange unit and hence assists the cooling action of the cooling unit, thereby increasing the efficiency of the system.
In practice, beverage in a container initially at approximately 12xc2x0 C., may be reduced over a period of say 24 hours to approximately 4xc2x0 C.
According to a second aspect of the invention there is provided apparatus for carrying out the method of the first aspect, the apparatus comprising a container for beverage;
a circulation loop supplied by the container;
a pump, a cooling unit and one or more dispensing taps in the loop; and
a heat exchange unit to exchange heat between the loop and the container.
In one embodiment, the heat exchange unit may comprise a jacket adapted to fit over a keg. The jacket may of flexible, rigid, or semi-rigid material. The latter may for instance consist of a fibre glass jacket with a foam insert, whereby the heat exchange unit is additionally thermally insulating. A heat exchange coil, e.g. of synthetic plastics tubing, may extend around the inside of the jacket so as to be in close proximity to the external periphery of a keg when the jacket is fitted over the keg.
In another embodiment, the heat exchange unit may comprise a plurality of panels adapted to be assembled together to form an enclosure or cabinet for the bulk container(s).
The control unit may comprise beverage temperature sensing means.
The cooling unit may for instance comprise an ice bank and at least one cooling coil.